Install

Draft — verify against the current release.

Prerequisites

Castwright runs the synthesis engines locally, so it needs a reasonably modern machine.

GPU. An NVIDIA GPU with 8 GB of VRAM is the benchmarked path — a gaming PC or gaming laptop generates at roughly real-time. On Apple-silicon Macs the engines run on the Mac’s GPU automatically (CUDA → Apple’s MPS → CPU selection is built in); it works, just slower than the NVIDIA path. Without any GPU the app falls back to CPU, which works but is the slowest option — treat it as a fallback, not a plan. The Kokoro engine (the default, English-only engine) and the Qwen voice-design engine both use whichever device is selected.

Operating system. Windows, macOS, and Linux are all supported — Windows or Linux for the NVIDIA path, macOS 12+ on Apple silicon. Windows is the most tested platform during early access.

ffmpeg. Castwright uses ffmpeg for audio assembly and loudness normalisation. It must be installed and available on your system PATH. Most package managers (Homebrew, Scoop, apt) have it.

Python environment. The synthesis sidecar runs in a local Python virtual environment. The installer sets this up for you on first run — you do not need to manage it manually.

Download

The canonical place to get Castwright is the site’s download page. Releases will also be published on GitHub when the public beta opens — until then, and after, the download page is where to look.

The beta ships as a zip — download it for your platform, extract it, and run the launcher. At launch this becomes proper installers: signed for Windows, notarised for macOS.

First run

On first launch Castwright will download the Kokoro voice weights (about 1 GB) and set up the local analysis model via Ollama if you have it installed, or fall back to a Gemini API key if you supply one. The in-app Model Manager (under the account menu) shows installation progress and lets you add optional engines like Coqui XTTS or the Qwen voice-design model.

If you run into trouble, see Troubleshooting or email hello@castwright.ai.